#117 Clearcase tasks have hardcoded 3 minute timeout

[kiwidude]

In the ClearCaseBase task class it sets a default
timeout of 3 minutes. Unfortunately this is not
reflected in the documentation for the class which
states it has an "unlimited timeout" - clearly
incorrect.

Confused the heck out of one of the developers here as
to why their CruiseControl.Net project kept timing out
when doing a <ccupdate> despite having long build
intervals.

The workaround is to use the timeout attribute on your
various long running Clearcase tasks. It would be nice
if the Clearcase tasks documentation all indicated
this rather than saying "unlimited".

Thanks.